import * as Cesium from '@cesium/Source/Cesium.js';
// import trailLinkImage from "@assets/img/6957972-c5f879cd86b79dfd.png";

/*
  流动纹理线
   color 颜色
   duration 持续时间 毫秒
*/
function PolylineTrailLinkMaterialProperty(color, duration, d) {
  this._definitionChanged = new Cesium.Event();
  this._color = undefined;
  this._colorSubscription = undefined;
  this.color = color;
  this.duration = duration || 3000;
  this._time = new Date().getTime();
  this._d = d;
  this.isTranslucent = function() {
    return true;
  };
}

Object.defineProperties(PolylineTrailLinkMaterialProperty.prototype, {
  isConstant: {
    get: function() {
      return false;
    }
  },
  definitionChanged: {
    get: function() {
      return this._definitionChanged;
    }
  },
  color: Cesium.createPropertyDescriptor('color')
});

PolylineTrailLinkMaterialProperty.prototype.getType = function(time) {
  return 'PolylineTrailLink';
};

PolylineTrailLinkMaterialProperty.prototype.getValue = function(time, result) {
  if (!Cesium.defined(result)) {
    result = {};
  }
  result.color = Cesium.Property.getValueOrClonedDefault(this._color, time, Cesium.Color.WHITE, result.color);
  result.image = Cesium.Material.PolylineTrailLinkImage;
  result.time = (((new Date().getTime() - this._time) % this.duration) / this.duration) * this._d;
  return result;
};

PolylineTrailLinkMaterialProperty.prototype.equals = function(other) {
  return this === other || (other instanceof PolylineTrailLinkMaterialProperty && Property.equals(this._color, other._color));
};

Cesium.Material.PolylineTrailLinkType = 'PolylineTrailLink';
Cesium.Material.PolylineTrailLinkImage = require('@assets/img/6957972-c5f879cd86b79dfd.png')
Cesium.Material.PolylineTrailLinkSource = `czm_material czm_getMaterial(czm_materialInput materialInput)
    {
      czm_material material = czm_getDefaultMaterial(materialInput);
      vec2 st = materialInput.st;
      vec4 colorImage = texture2D(image, vec2(fract(st.s - time), st.t));
      material.alpha = colorImage.a * color.a;
      material.diffuse = (colorImage.rgb+color.rgb)/2.0;
      return material;
    }`;
Cesium.Material._materialCache.addMaterial(Cesium.Material.PolylineTrailLinkType, {
  fabric: {
    type: Cesium.Material.PolylineTrailLinkType,
    uniforms: {
      color: new Cesium.Color(0.0, 0.0, 1.0, 0.5),
      image: Cesium.Material.PolylineTrailLinkImage,
      time: -20
    },
    source: Cesium.Material.PolylineTrailLinkSource
  },
  translucent: function(material) {
    return true;
  }
});

export default PolylineTrailLinkMaterialProperty;
